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When is “i += x” different from “i = i + x” in Python?
I was told that += can have different effects than the standard notation of i = i + . Is there a case in which i += 1 would be different from i = i + 1 ?
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How to copy a dictionary and only edit the copy
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It might be better to say "dict2 and dict1 point to the same dictionary", you are not changing dict1 or dict2 but what they point to.
– GrayWizardx
Mar 17 '10 at 21:15
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Meaning of numbers in “col-md-4”,“ col-xs-1”, “col-lg-2” in Bootstrap
...ns in a .row, which has -15px margins. This avoids duplicating the padding and keeps the content lined up between nested and non-nested col classes.
-- You didn't specifically ask about the xs, sm, md, lg usage, but they go hand-in-hand so I can't help but touch on it...
In short, they are used t...
Mod of negative number is melting my brain
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@RuudLenders: No. If x = -5 and m = 2, then r = x%m is -1, after which r+m is 1. The while loop is not needed. The point is that (as I wrote in the answer), x%m is always strictly greater than -m, so you need to add m at most once to make it positive.
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Delete multiple records using REST
...things that don't make sense from your point of view.
This choice is best, and can be done RESTfully. If you are creating an API and you want to allow mass changes to resources, you can use REST to do it, but exactly how is not immediately obvious to many. One method is to create a ‘change request...
How to calculate time elapsed in bash script?
I print the start and end time using date +"%T" , which results in something like:
20 Answers
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What does O(log n) mean exactly?
I am learning about Big O Notation running times and amortized times. I understand the notion of O(n) linear time, meaning that the size of the input affects the growth of the algorithm proportionally...and the same goes for, for example, quadratic time O(n2) etc..even algorithms, such as permu...
Why is my program slow when looping over exactly 8192 elements?
...rom the program in question. The matrix img[][] has the size SIZE×SIZE, and is initialized at:
2 Answers
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Benchmarking (python vs. c++ using BLAS) and (numpy)
I would like to write a program that makes extensive use of BLAS and LAPACK linear algebra functionalities. Since performance is an issue I did some benchmarking and would like know, if the approach I took is legitimate.
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Is it safe to check floating point values for equality to 0?
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It is safe to expect that the comparison will return true if and only if the double variable has a value of exactly 0.0 (which in your original code snippet is, of course, the case). This is consistent with the semantics of the == operator. a == b means "a is equal to b".
It is not sa...